Elevator control.



J. 1). I HLDER. ELEVATOR CONTROL. APPLICATION FILED 001231.,1908.

1,040,546. Patented Oct. 8,1912. Y 2 sums-sum 1.

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ELEVATOR CONTROL.

APPLIUATION FILED OOT,81,1908.

Patented 0dt.8,1912.

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JOHN D. IHLDEB, OF NEW YORK, N. Y., ASSIGNOR '10 OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

ELEVATOR CONTROL.

ratentedo'ctis, 11912.

Application filed Qetober 31, 1908. Serial No. 460,525. I

To all whom it may concern:

Be it known that I, JOHN D. IHLDER, a citizen of the United States, residing in New York, in the county of New York and State of New York, have invented a new and usestul Improvement in Elevator Control, of which the following is a specification.

My invention relates to improvements in push-button elevators, and one of its objects is the provision of means formaking an eizact landing at any predetermined point under varying loads without depending upon the skill of the operator.

A further object of the invention is the provision of means under the control of the operator for automatically making an exact landing. \1

Other objects of my invention will appear hereinafter, the novel combinations of elements being set forthin the appended claims.

In the accompanying drawings, Figure 1 is a complete wiring diagram of an automatic controlling system for electric elevators embodying my invention; Fig. Qis a fragmentary wiring diagram showing a portion of Fig. 1; Fig. 3 is a wiring diagram similar to Fig. 2 showing a modification; and Fig. 4 is a wiring diagram showing a further modification.

Similar reference characters denote similar parts throughout the figures.

My invention relates more particularly to an improvement upon the system of elec trical operation of elevators shown and described in Patent No. 683,689, granted to me on October 1, 1901, for an improvement in electric operation of elevators.

lVhile my, present invention, as shown, embodies substantially the same general arrangement of electrical circuits as shown and described in Patent No. 683,689 before referred to, and the ends sought to be attained are of. the same general character as the objects hereinbefore set forth, my improvement consists in so arranging the circuits for ccntrollin the elevator motor that, after the 'car has con startedby pressing any one of the push-buttons and has finally come to rest at the particular floor or landing to which it was sent, by pressing anadditional button the car will move neither direction a shortdistance only.

7 ,In push-button operated elevators in which the destination "of the car is determinedby pushing a. corresponding button,

the entire operation of the elevator app ratus as regards starting, accelerating,'stopping and reversing is performed automati; cally. In such elevator systems it is found that the car will not always stop exactly at the desired landing, due to varying-loads carried in the car. That is to say, if the elevator apparatus is adjusted to automatically 4 stop adjacent any floor landing with a certain load, by varying this load the car will tend to overrun or fall short of an exact landing by a small amount. Thile in general this feature is of small moment, particularly where the elevatouis, used for pas senger service alone, in many cases it is very desirable, if not absolutely necessary, to effect an exact landing of the car regardless of the load; such is the case where trucks are to be loaded or unloaded from the car. To eii'ect such an exact landing without depending upon the skill of the operator, and without a refined or complicated system of control, I provide ai simple controlling system which will automatically bring the car substantially adjacent the desired floor landing, varying more or less according to the load, and I then provide additional push buttons, one for an upward motion and one for a downward motion, and having circuits connected thereto, so that upon pressing one of these buttons the car will move a short distance only, several applications of the button being necessary to effect a longer movement. Or these buttons may be so arranged that they need not be operated several times to give a longer movement, a single operation of .a button causing the car to move in automatic successive steps, allowing the operator to stop the movement at any ste or when the car 1s exactly opposite the desired landing.

The following description taken in connection with the accompanyin drawings shows how I purpose to accomp ish the desired ends. a

In the drawings the heavy black lines repallow the motor to rotate, the brake being applied at all other times. S designates a motor-reversing switch, and, while this switch may vary in construction and operation, I prefer the construction shown and described in my patent before referred to. It comprises two oppositely arranged electro-magnets D and U which operate when energized to move an armature 16 upon which is mounted a series of contacts 17, 18, 19 and 21 adapted to electrically engage corresponding fixed contacts ar ranged on either side of the contact carrier 16. The fixed contacts 'are designated'by 22, 23, 24 and 25 on one side, and.22', 23, 24 and 25' on the other. side. 26 and 27 designate non-interference contacts which are normally in engagement with eac. other, but which have moved out of cor.- tact by the contact carrier 16 when the latter is moved to one side or the other by the magnets D or U. A designates an accelerating magnet which operates to cut out or short-circuit the starting resistance R and series field winding 20. 30 is the shunt "field winding which remains energized whenever the motor M is in operation. A push-button switch 70 is arranged at each floor landing, while door contacts 71 are arranged upon the doors at these landings. The car contains a series of push-button switches 10, each button corresponding to a floor; also a safety switch 29 and car gate contact 28. Other push-button switches 31 and 32 are carried in the car. The floor buttons 70 and car buttons 10 are connected to corresponding relays 40 which are connected by means of the brushes 41, 42, 43 and 44 to a floor controller F. This floor controller F comprises two contact segments 47 and 48 which are adapted to make contact with the stationary brushes 41, 42, 43, 44, 45 and 46, the brushes 45 and 46 being connected to the reversing switch mag nets U and D, respectively. The conductmg segments 47 and 48 may be mounted upon some suitable insulating base which is arranged to be rotated will harmony with a moving part of the elevator apparatus, such as the hoisting drum shaft. The magnet 50 is a doubly wound magnet having its windings connected in opposition, while the magnet is asafety c'ar magnet. -iand designate conductors which connect the system of electrical circuits to some suitable source of electrical-supply.

The drawing shows the carat rest at the third floor landing, the operating circuit being'broken at the contact brush 43 of the floor controller. In order to show the operation of the ap1iaratus let it be assumed that the floor button 70 at the second floor is pressed. This establishes a circuit as follows: from the main through the safety switch 29, car gate contact 28, landing door contacts 71, windings 51 and 52 of magnet 50, normally closed switch 53, contact 55 controlled by the accelerating magnet A, wire 49, push-button at the second floor, wire 33, relay 34, brush 42, contact segment 47, brush 46, to and through the reversing switch magnet 13, and by wire 35, contacts 27, wire 13, contacts 37, and wire 38 to the main. This circuit justtraced includes the magnet winding of the floor'relay 34 and the reversing switch magnet D, both of which will become energized. The magnet 34 closes the switch 36 while the magnet D operates the reversing switch S, so that the contacts 17, 18, 19 and 21 carried upon the bar 16 are moved into electrical engagement with the fixed contacts 22, 23, 24 and 25, respectively. The bar 16 at the same time opens the switch 26. Upon closing the switch 36 a circuit is established through this switch and the resistance 54, which circuit is parallel to the circuit through the winding 52 of the differentially wound magnet 50 and the push-button 70, and the current in this winding 52 is thereby reduced to such an amount that the winding 51 is enabled to separate the contacts 53 and thusopen the circuit for all of the pushbuttons 70 through the wires 39 and 49. As soon as the switch 36 is closed, the pushbutton 70 at the second floor may be released, the controlling circuit being maintained closed at this switch until it is finally broken at the desired moment by through the motor armature to brush .a, contacts 24 and 19, and by wire 72 to the negativemain. The shunt field 30 and brake magnet B are connected directly across the mains through the wires 69 and contacts 17 and 22 on one side and the wire 72 on the other side. -The motor M therefore receives current which is limited in amount by the resistance R, and runs at slow speed, the brake being released bythe energization of its magnet B. The motor is automatically brought'up to full speed by means of the accelerating magnet A, the winding of which is connected across the brushes 0 and b of the motor upon the closing of the retacts 18 and 23 to the brush 7), thence versing switch SF The accelerating magnet field 20, and thus bringing the motor up to full speed, the direction of rotation of the motor being such as to cause the elevator car to descend. The closing of the switches 57 and 64 opens the switches 55 and 59 which interrupts the circuitthrough thefloor switches 70 and through the car switches 10, thereby rendering these push-buttons inoperative while the car is in motion.

The rotation of the motor will cause the floor controller segments 47 and 48 to rotate in a clockwise direction, and it will be seen that the operating circuit before described will be maintained until these segments have rotated sufiiciently to allow the segment 47 to move out of electrical engagement with the brush 4:2"which will break the circuit of the reversing switch magnet D, releasing the bar 16 of the reversing switch and stopping the motor, the elevator car coming to restat the second floor. It will be seen that when the controlling circuit is opened by the rotation of the floor controller segments when the car has arrived at the desired floor landing, the magnet 50, together with the other magnets in circuit, becomes deenergized, so that the system is again in position to be operated by pushing any par ticular push-button.

In case one of the car buttons 10 is pushed, the operating circuit is somewhat different than the circuit established by operating one of the floor buttons. To illustrate this operation, let itbe assumed that the car is at the third floor landing as before, and one of the car buttons 10 corresponding to the sec ond floor is pressed. The operating circuit is now closed from the main through the safety switch 29, car gate contact 28, landing doorcontacts 71, winding 51 of the differential magnet 50, winding 61 of the safety car magnet 60, switch 59 of the accelcrating apparatus, wire 73 to the car switches 10, and from here on the circuit continues through the floor relay 34, floor controller contacts, and reversing switch magnet D as before pointed out in connec tion with a floor button operation. The winding 52 of the magnet does not receive current, hence the magnet winding 51 is enabled to immediately separate the contacts 58, thereby open-circu1ting the floor buttons .70 and rendering them inoperative.

Since the circuit includes the magnet 60, the same is energized; to close the switch 62 which establishes a local circuit through the windingfil, winding 61, contacts 62, and resistance63Q It is readily seen that this local circuit is not opened by the floor controller when the car reaches its destinat-ion and the motor is stopped, and as long as this circuit remains closed it'is impossible to again start the car by operating any one of the floor buttons, sinc'e their circuit is open at the contacts 53' of the relay 50. In order to tion of the motor when it is being operated from the car, and vice versa, and to prevent interference from either set of buttons when the motor is running, the back contacts 55 and 59 have been provided. The contacts 55 being in a circuit which supplies current to the floor buttons 70, while the contacts 59 are in a circuit which supplies current to the car buttons 10, it is readily seen that when the motor is running and these contacts have been'separated by the accelerating magnet A, any operation of either the car or floor buttons has no efiect on the system until after the motor has come to rest with the car at its destination.

WVhen it is desired to send the car to an upper floor, the operating circuit is substantially the same as before, excepting in this case the circuit is closed through the segmental contact 48 and reversing switch magnet U. The latter upon becomingenergized swings the contacts 17, 18,19 and 21 into engagement with the fixed contacts 22',

23, 24 and 25, respectively, the circuits to the motor being the same as before excepting that the current flows through the motor armature in a reverse direction, that is, from the brush a to the brush b, and consequently the motor will rotate in an opposite direction and thus effect an upward movement of the elevator car C. It will be noticed that when the magnet D is energized to operate closed switches 65 and 66 are arranged to be opened by the car when the same overruns its normal limit of travel in either an upward or downward direction, thereby opening the circuit to the motor and stopping the car. This description of a push button controlled elevator system is substantially the same as given in the patent before referred to, and, while such system is preferred by me for many reasons, other systems of elevator control which operate to bring an elevator car approximately to a landing maybe used. In allsuch systems of elevator control, there is always the tend ency for the elevator car to overrun or. fall short of an. exact landing, due-to varying loads in the car, and I will now describe the means by which ll bring the car from an approximate to an exact level with the landing. i

In addition to the push-buttons 10 and 70, by means of which the movements of the car are normally controlled, I provide pushbuttons -or other circuit-closing devices 31 and 32 which may be located in the car C as shown or located at the floor landings or other suitable places as desired. These buttons are similar to each other, and each comprises two movable contacts, as 74 and 75, and three fixed contacts, as 76, 77 and 78. The contact 74 is adapted to engage both of the contacts 76 and 77, while the contact 75- is adapted to engage the contact 7 8 when the button 31 is pressed.

5 designates an electrically operated switching device comprising two magnet cores 8 and 9 connected together andmovable into the magnet windings 7 and 14, respectively. Each magnet when energized tends to lift its core and thereby separate the contacts 37 below and connect the con tacts 6 above.

in order to illustrate the operation of the switches 31 and 32, let it be assumed that the elevator car is heavily loaded, and, after traveling from an upper floor, has been automatically stopped at the third floor landing, the heavy load in the car causing the latter to overrun .the exact floor level. An operator at this floor desires to bring the car exactly opposite the floor level and he steps into the car and presses the push-button 31 corresponding to an upward movement of the car. The operation of the button 31 closes circuits which are as follows: from the positive main to the contact 7 4 and contacts 76 and 77. The circuit does not continue by way of contact 76, since this contact is open-circuite'd at the contacts 6. circuit is closed, however, ,through the contact 77 by way of the wire 12, magnet U of the reversing switch, through the non-interference contacts 26, and by Way of wire 13, contacts 37 and wire 38 to the negative main. The magnet U is thus connected directly across the mains, and the reversing switch S immediately operates to close the motor and brake circuits in a direction to cause the car to ascend. At the same time that the through the contact 77, the contact 75 eled trically engages the contact 78, thereby connecting the magnet winding 14 in parallel with the motor armature. This circuit may be traced as .follows: from the brush a through the contacts 23 and 18, wires 67 and 81, contacts 75 and 78 of the push-button switch 31, wire 15, magnet w nding 14, wires 38 and 72, reversing switch contacts 19 and 24, and to the armature brush 7). The 'magnetwinding 14 is so adjusted that it will become suflicientlyfenergized toliit its push-button contact 74 closes a. circuit core 9 and thereby separate the contacts 37 when the motor armature attains a predetermined speed, which may be a few revolutions or nearly full speed, as desired. This adjustment limits the distance which the car will travel, since, when the magnet 14 lifts its core and separates the contacts 37, it opens the circuit through the reversing switch magnet U at these contacts and the reversing switch opens the motor and brake circuits and stops the motor, hoisting apparatus and car. The contacts 6 of the magnet switch 5 are brought together at substantially the same time that the contacts 37 are separated, and by bringing the contacts 6 together a circuit is closed from the main through the push-button contacts 7 4 and 76, wire 7 9, contacts 6, magnet winding 7, and by wire 38 to the main. The magnet winding 7 is thus connected through the push-button 31 directly across the mains and this circuit is maintained closed as long as the push-button 31 is held compressed. It is readily seen that as long as the pushbutton 31 remains in closed position and the core 8 is held up by the magnet 7, the contacts 37 willv be separated, thereby opencircuiting the reversing switch magnet U versing switch from again being operated to start the motor. As soon, however, as the push-button 31 is released and the circuit through the winding 7 is broken at the push-button contacts 76 and 74, the cores 8 compressed, giving the car a further upward movement, and this button may be operated as many times as is necessary to bring the car exactly opposite the required floor level.

The distance which the car will move at each operation of the push-button depends upon the adjustment of the magnet switch 5. Since the winding 14 is connected by the push-button 31 directly across the motor armature, its magnetizingzpower is proportional to the voltage across the motor armature, and as this voltage or drop in potential is substantially proportional to the through the wire 13 and preventing the recounter-electro-motive force and speed of the motor, the adjustment of the magnet switch 5 may be made by varying the number of turns on the winding 14, or by regulating the position of the magnet core 9 with respect to the magnet winding 14, or by varying the weight of the core 9, or in other well known ways. In thismanner the magnet switch 5 may be made to operate when the motor has made a few revolutions only or not until the motor has come up to full speed, the distance of car travel for each application of the push-button being thus regulated from a fraction of an inch to several inches or more, as desired. Since each operation of the push-button 31 allows the car to move'only a limited distance, an inexperienced operator may readily bring the car exactly to the desired floor level without danger of overrunning.

Should the elevator car automatically stop at a point above the desired floor level, the push-button 32 corresponding to a downward movement of the car is operated. In this case a circuit is closed through the magnet D of the reversing switch by way of the push-button contact 77, and the reversing switch is operated to start the motor in a direction to lower the car, the operation of the magnet switch 5 being precisely the same as when the button 31 was operated. As before pointed out, the magnet winding 1 is connected through either of the push-buttons 31 or 32 across the armature brushes, and this circuit is only closed when the reversing switch S is operated; and since the connection of this magnet to the armature brushes is made upon the connection into circuit of the reversing switch contacts18 and 19, it follows that the circuit through the magnet winding 14 is never reversed in direction, ,hence the magnet switch 5 responds more quickly to the varying voltage at the armature brushes as the motor accelerates in speed. I sometimes find it advantageous to connect the mag net winding 14 in such manner that it not only spans the motor armature, but also a part of the starting resistance B. This connection is illustrated in Fig. 3.

Referring to Fig. 2, which is a fragmentary diagram taken from Fig. 1 and showing the circuit of the magnet winding 1.4:, it is seen that the wire 81 is connected to a point on the motor circuit between the motor armature and the starting resistance. This is the arrangement as described in connection with Fig. 1. In Fig. 3 the same arrangement of circuits prevails, excepting here the wire 81 is connected to some point on the starting resistance R in such manner that the terminals of the winding 14 not only span the motor armature, but also a portion of the starting resistance. The amount of resistance R included in the circuit may be varied at will by changing the connecting point of the wire 81 with the resistance.

In a modification of my deviceit is not necessary to operate the push-buttons 31 or 32 a number of times in order to produce a corresponding periodic movement of the. elevator .car, a single pressure on the push-button producing automatic successive steps of movement of the car, allowing the operator to stop this movement at any time by merely releasing the push-button. In this manner the car will move along a short distance at a time until the desired iloor level is reached, when the operator releases the button and the car comes to rest. I accomplish the above result by leaving off the push-button contacts 76 and 76 and also doing away with the magnet winding 7 core 8, and contacts 6.

The wiring diagram thus modified is shown in Fig. 4: and the operation is as follows:

Upon pressing the push-button 31, two circuits are closed, one of which is from the positive main through contacts Hand 77, wire 12, resistance 80, reversing switch magnet U, contacts 26, wire 13, contacts 37, and by the wire 38 to the negative main;- the other circuit is from the armature brush a through contacts 75 and 78, Wire 15, magnet winding 14, to the armature brush 6. The first-named circuit includes the resistance 80, reversing switch magnet U, and contacts 37 The reversing switch is therefore operated and closes the motor circuits, causing the car to ascend. The second-named circuit connects the magnet winding 14 across the armature brushes a and Z), and this magnet winding will gather strength as the motor increases its speed until it is powerful enough to lift its core 9 and thereby separate the contacts 37. Assoon as these contacts become'separated, the circuitthrough the reversing switch magnet U becomes broken and the motor circuit is thereby opened and theelevator car comes to rest. As the motor comes to rest the current in the magnet winding 1 L ceases and the contacts 87 once more come into electrical engagement with each other, again closing a circuit through the re versing switch magnet U, and the same op eration or cycle of operations is repeated. Thus it is seen that as long as the button 31' remains compressed the elevator car will automatically move a short distance, stop, and then move again, this succession of steps being repeated until the push-button is finally released. The operation of the push button 32- produces similar results, only in this case the magnet l) of the reversing switch is energized and the car travels in an opposite direction. While the magnet winding 14 of Fig. 4 may be connected through the reversing switch contacts across the armature brushes as shown in Fig. 1, I prefer to connect the terminals of this magnet directly to the armature brushes, thereby producing a longer time interval for each step instead of having the circuit of the magnet l i broken as soon as the reversing switch llll opens its contacts, the current dying out as in circuit with them one of the floor relays,

the resistance 54, and the winding 51 of magnet 50. i

It is evident that my invention as applied to an automatic system of elevator control enables an unskilled operator to make an exact landing, regardless of the position of the car with respect to said landing and without danger of overrunning the landing.

Obviously those skilled in the art may make various changes in the details and arrangement of parts without departing from the spirit and scope of the invention as defined by .the claims. I wish, therefore, not to be limited to the precise construction here- K in disclosed.

What I claim is 1. In an elevator system, the combination with a car, of automatically controlled apparatus for bringing thecar to any desired floor landing, and automatic means for effecting a small additional movement or movements of the car.

2. In an'elevator system, the combination with a car, of a motor, apparatus for operating the motor to bring the car to rest at or near any desired floor landing, and means for effecting a short additional movement of the motor in either direction.

I 3. Tnan elevator system, the combination with a car, of an electric motor, controlling mechanism for automatically effecting the travel of the car through a predetermined distance,and manually operable means for controlling the motor circuits to efiect a small additional movement or movements of the car. I

4. The combination with an electric motor, of controlling circuits and mechanism for effecting the operation of the motor through comparatively long ranges of movement, and additional circuits and connections for eifecting successive movements of the motor through short distances only.

5. The combination with an electric motor, of controlling circuits and mechanism for automatically effecting the normal operation of the motor, and automatic means for effecting step-by-step movementsof the motor.

6. The combination with an electric motor, of controlling and operating circuits and mechanism therefor, means for eflecting short operations of said motor and means depending upon the counter-electro-mot1veforce of said motor for automatically cutting oil? the current supply after each short operation of the motor.

7. The combination with an electric motor, of automatically controlled means for imparting a continuous rotation to the motor armature during its normal operation, and automatic means for effecting a step by step operation of the motor.

8. The combination with an electric motor, of controlling circuits and mechanism for effecting a continuous rotation of the motor armature during its normal operation, rand manually controlled means for automatically eflecting an intermittent rotation of the armature through a series of short steps.

9. The combination with an electric motor, of means for supplying current thereto, and means dependent upon the motor for automatically cutting ofi the current supply to stop the motor betorethe motor has reached its normal speed.

- 10. The combination with an electric mo with the motor armature and designed to open the switch before the motor reaches its normal speed.

12. The combination with an electric motor comprising a rotary armature, of acontrolling circuit for the motor, a normally open push-button switch 'in said circuit, and a normally closed electro-magnetic switch in said circuit and having its magnet winding connected across the motor armature and designed to open the normally closed switch when the motor has developed a fraction of its normal counter-electro'motive force.

13. The combination with an electric motor comprising a rotary armature, of an electro-magnetic reversing switch, a normally open circuit including a magnet winding of the reversing switch, means for closing said circuit, a normally closed switch in said circuit, and an electro-magnet for operating said last-named switch and having its windingconnected-to receive current varying with the'speed of the armature and designed to open the switch when the armature has developed a fraction only of its normal speed.

14:. The combination with an electric mo tor comprising a rotary armature, of a controlling circuit, a normally open pushbutton switch in said circuit, a normally closed switch in said circuit, means for automatically opening said normally closed switch when the motor has developed a frac I tion of its normal speed, and a device for holding said last-named switch open when said means has operated.

an electro-magnetic device comprising a normally closed switch 1n said clrcuit and a normally open switch, a magnet w'mdmg for said device in a circuit in parallel with I the motor armature, a second magnet wmd- 2o ing for said device, and a circuit therefor including said normally open switch and also normally open atsaid manual switch. v

In testimony whereof, I have signed my name to this specification in the presence of two subscribing witnesses.

- JOHN D. IHLDEB. WVitnesses Jon: B. Evens,

JAMES G. BETHELL. 

